On Saturday, the Houthis seized the state television building, a central symbol of the government’s power. State media reported Saturday night that military units were moving to recapture it, but instead the Houthis appear to have willingly turned over the site to the military police, a force that is regarded as independent of the government and perhaps potentially sympathetic to the rebels.

By Sunday afternoon, certain military units, including the Fourth Army Brigade and a military leadership center, had appeared to shift their support to the Houthis instead of the government, perhaps switching loyalties to back the winning side. The Houthis and their military allies had control of the state radio building as well as the state television building and the prime minister’s office.

Image Prime Minister Mohammed Salem Basindwa of Yemen, who resigned on Sunday. Credit Mohammed Huwais/Agence France-Presse — Getty Images

As Houthis surrounded the building housing the Interior Ministry, the ministry issued a conciliatory statement saying that it had ordered the police to “cooperate” with the rebels “in consolidating security and stability.” The ministry called the Houthis “friends of the police in the service of the general interest of the homeland.”

Elsewhere, Houthi forces continued to battle other military units, most notably a major division considered loyal to Brig. Gen. Ali Mohsin al-Ahmar. One of the fragmented military’s most important commanders, General Ahmar comes from a powerful tribe and his family also has a leading role in Yemen’s mainstream Sunni Islamist party, Islah. Islah and the Ahmars both played major roles in the protests that forced out President Saleh, and they are considered political rivals of the Houthis.

They were also among the losers in the past week’s battles. By nightfall on Sunday, the Houthis had taken the headquarters of General Ahmar’s First Armored Division, according to security officials and news reports. The general’s whereabouts was unknown.

Prime Minister Mohammed Salem Basindwa, who resigned Sunday, is also linked to the Islah party, and the Houthis and others have accused him of corruption. But the circumstances of his decision were not completely clear.

“I have decided to tender my resignation from the government out of my concern to pave the way for any agreement reached between the brother leaders of Ansarullah” — the party of the Houthis — “and brother Abdu Rabbu Mansour Hadi, the president of the republic,” the prime minister wrote in a letter of resignation, according to Reuters.

Houthi news outlets, meanwhile, published a version of the letter in which the prime minister accused President Hadi of corruption. Its authenticity could not be confirmed.